The present invention relates to semiconductor device fabrication, and in particular, to a replacement metal gate process.
A replacement metal gate (RMG) process, i.e., a gate last process, has been traditionally used in semiconductor fabrications processes to form a semiconductor device including one or more gate elements 102 that wrap around on one or more semiconductor fins 104. The gate elements 102 typically extend in a direction perpendicular to the direction of the semiconductor fins 104 as illustrated in FIG. 1. The RMG process utilizes a dummy gate element formed from amorphous silicon (a-Si) or polysilicon (PC), which is ultimately replaced with a metal gate element as understood by those ordinarily skilled in the art. However, the silicon material of the dummy gate element may be exposed when recessing the spacers formed on the sidewalls of the dummy gate element. Consequently, epitaxial material may be inadvertently grown on the exposed silicon of the dummy gate element which may result in a short between the epitaxially grown source/drain regions and the epitaxial material grown on the gate element.